Thermostatic device



Sept 10, 1929- J. SIMMONS ET AL 3,728,012

I THERMOSTATIC DEVICE Filed June 18, 1928 /Q.\' 5 I J.

INVENTORS Jaw/V J. 51mm 0N5 Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

JOHN J. SIMMONS AND RALPH J. DELANEY, OF PHILADELPHIA, PENNSYLVANIA, AS- SIGNORS OF ONE-THIRD '10 J". N. M. SHIMER, OF PHILADELPHIA, PENNSYLVANIA.

THERMOSTATIC DEVICE.

Application filed June 18,

Our invention relates to a new and useful thermostatic device whereby temperature is automatically and accurately controlled and regulated.

Our invention further relates to a thermostatic device wherein the terminals of an electrical conductor carrying electrical energy are electrically connected or closed to complete the circuit by the introduction of a conducting fluid into the chamber, wherein said terminals are positioned, said terminals being disconnected to open the circuit by the withdrawal of said conducting, connecting fluid, the introduction and withdrawal of said conducting connecting fluid into and out of the chamber containing said terminals being automatically effected and controlled by the rise and fall of the temperature to which the device is subjected and by the particular degree of heat desired to be maintained and to which the device is set.

Our invention further relates to a thermostatic device of this, character which is capable of accurate adjustment to various de- 1 grees of heat, that is, one which is capable of being set or adjusted to maintain any desired degree of temperaturewithin the range of ordinary requirements.

Our invention further relates to a thermostatic device which is capable of controlling and regulating a plurality of temperatures automatically, to the end that heating and cooling effects can be had in rapid succession so that a predetermined temperature may be uniformly and accurately maintained without any intervening overheating or underheating stages.

Our invention further relates to a novel construction of a thermostatic device of an extremely sensitive nature, that is, one in which external changes of temperature are exaggerated or multiplied, so that slight fractional changes of temperature may be instantly detected and indicated, thus rendering our novel device highly accurate and capable of adjustment within narrow limits.

To the above ends, our invention consists of a U-shaped tube, having the upper end of one limb thereof closed and provided with an adjustment plunger, a fluid, as mercury or the 1928. Serial No. 286,363.

like, in the U-shaped portion of said tube, a movable differential piston or plunger in the upper end of the other or longer limb of ,said tube, having its upper end recessed to form a cup, there being a port in the bottom of said cup, and its bottom portion comprising a reduced pendant stem or plunger integral therewith and adapted to reciprocate in a lower cylinder or chamber in the body portion of said limb, the top of which is closed; an overflow pocket surrounding the upper end of said lower chamber and communicating therewith, an upper pocket having upper and lower ports adapted to register and communicate with the top and bottom of said cup when ,said plunger is in its extreme lower and upper posit-ions respectively, electrical terminals positioned in said cup, and means for insulating said terminals from each other.

Our invention still further consists of novel means for vertically guiding said movable plunger and preventing the rotation thereof.

Our invention still further consists of various other novel features of construction and advantage, all as will be hereinafter described and claimed.

For the purpose of illustrating our invention, we have shown in the accompanying drawings two forms thereof which are at present preferred by us, since the same have been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which our invention consists can be variously arranged and organized and that our invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

In the accompanying drawings, which are on a greatly enlarged scale.

Fig. 1, represents a vertical sectional view of a thermostatic device embodying our invention, shown in the off or circuit breaking position, certain parts being shown in elevation.

Fig. 2, represents a view similar to Fig. 1, showing our novel. thermostatic device in the on or circuit making position.

Fig. 3, represents an end elevation of the upper, right hand portion of Fig. 1.

Fig. 4, represents a side elevation of the differential piston or plunger employed, in detached position.

Fig. 5, represents a view similar to that of Fig. 3, showing a modified form of our novel construction.

Referring to the drawings, in wiich like reference characters indicate like parts, 1 designates a thermostatic device embodying our invention, comprising a U-tube having the vertical limbs 2 and 3 of different lengths and the bottom connecting portion 4, in which is contained a fluid 5, such as mercury or the like. The limb 2 is closed with a suitable cover 6 having the boss 7 through which is threaded the stem 8 carrying the adjusting plunger 10 and the upper head or knob 9 for manually actuating said stem and plunger. The limb 3 is provided with the solid or cylindrical portion 12, having the piston or plunger chamber 13, which communicates at its upper end with the annular overflow passage pocket 15, the bottom walls 16 of which are inclined as will be understood from Figs. 1 and The pocket is provided with an integral, upper tubular extension 17 forming an enlarged piston chamber, in which slides the plunger or piston 18 having the pendant, integral stein reduced plunger 19 which is adapted to reciprocate its chamber 13, as will be seen from Figs. 1 and 2. The upper end of the plunger 18 is dished or recessed to form the cup 20 which is provided with the bottom outlet port 21 which is adapted to register with the unoer port 22 of the side pocket or passage 24, when the plunger 18 is in its uppermost posit on (see Fig. 1) the lower port 25 of said side pocket 24 being adapted to register with the top of the cup 20 when said plunger is in its lowermost position (see Fig. 2). To insure constant and accurate alignment of the port 21 of the plunger 18 with the port 22 of the side pocket 24, a guide stem or rod 27 is provided, adapted to pass through the opening 28 in said plunger, the lower end of said stem being integral with or secured to the up per wall 29 of the overflow pocket 15, as will be understood from Figs. 1 and 2. 3O designates a vertical partition that extends upwardly from, and is integral with or secured to the bottom of the cup 20 and serves to space the electrical terminals and 32 to prevent accidental contact or arcmg, the upper ends of said terminals being secured to the contact stems 33, which are rigidly secured and sealed in the upper closed end of the extension 17, as will be understood from Figs. 1 and The stems 33 project outwardly through the end portion 35 and are connected to the terminals 37. The electrical terminals 31 and 32 are formed of flexible wire and are provided with the bottom weights 38 which tend to maintain said wires in extended or taut position when the differential piston 18 is in its lowermost position.

The operation is as follows:

Assuming the device to be in the position shown in Fig. 2, the plunger 18 is in its lowermost position, with the lower end of the reduced pendant stem 19 flush with the bottom of the cylinder 12, and floating on the top level 40 of the mercury 5 in the limb 3, which is on the same level as the mercury in, the limb 2. The adjustment plunger 10 is set so that its bottom contacts with the top of the mercury at the level 41 in the limb 2. As the mercury 5 expands due to heat, and due to the fact that the adjustment plunger 10 is stationary or set, the reduced stem or plunger 1.9 is moved upwardly in the chamber 13 to provide room for the expansion of the mercury. As the reduced stem or plunger 19 rises in its chamber 13, the plunger 18 also moves upwardly to the position seen in Fig. 1, wherein the mercury 42 contained in the on 20 in the top of said plunger drains throng 1 the ports 21 and 22 into the side pocket 24, the lower opening 25 of which is closed by the side of the plunger 18 (see Fi 1). The partition 30 is provided with a bottom port 43 through which the mercury on either side of said partition may drain into said pocket. When the mercury has been drained into the pocket 24, contact between the terminals 31 and 32 ceases and the circuit is broken, the parts now appearing as seen in Fig. 1. When the temperature has fallen below a predetermined limit, and the mercury 5 has contracted to its normal volume, the plunger 19 descends in its chamber 13 together with the plunger 18, so that the side thereof clears the lower, port 25 of the pocket 24, and the mercury 42 contained therein now flows into the cup 20, and passing through the port 43 in the partition 30, it again closes the circuit between the terminals 31 and 32, the parts now appearing as seen in Fig. 2. Thus, by the expansion and contraction of the mercury 5, the plunger 18 and its adjuncts are raised or lowered to discharge or receive the contact reaking or making mercury 42, which is alternately held in the pocket 24 and the cup 20, as above explained. hen the plunger 18 is in the lower position seen in Fig. 2, the weights 38 serve to extend or keep taut the wire terminals 31 and 32, so that their lower ends will be submerged in the mercury 42 in the cup 20 to complete the circuit. lVhen the plunger 18 is in its uppermost position and the mercury 42 has been drained into the side pocket 24 to break the circuit, the terminals 31 and 32 flex within the cup 20 and are prevented from coming together to make a circuit, by the insulating partition 30, as will be understood from Fig. 1.

By providing the adjustment piston or plunger 9 in the limb 2, we are enabled to regulate the amount of expansion of the mercury, by varying the amount of volumetric or cubic capacity of the U-shaped tube 4 without varying the volume 6 of the mercury 5, so that the device may be set to any number of varying degrees of heat and so that the visible indiciamay be set to represent any desired absolute value.

Thus, when the device is set to the position shown in Fig. 2, that is, with the mercury normally at the same level in the limbs 2 and 3, an increase of degrees in temperature will raise the plunger elements 18 and 19 one quarter of an inch (see Fig. 1). It is obvious that by raising the plunger 10 (by turning the hand wheel 9 to the left) the space or cubic capacity of the U-shaped portion 4 is increased and the mercury 5 will have room in which to expand prior to exerting any force on the bottom of the plunger 19, it being understood that due to the weight of the mercury, the net result of such an adjustment is determined by the difference in Weight between the columns of mercury in the limbs 2 and 3, minus the weight of the plungers 18 and 19 and the index of friction.

In this way the degree of temperature to be maintained is raised. Furthermore, if the plunger 10 is lowered, to raise the level of mercury in the opening 13 and therefore initially to raise the plungers 18 and 19, it is obvious that it will take only a slight increase in temperature to raise the plungers 18 and 19 into their uppermost position in which the mercury 42 is drained into the pocket 24 and the electric circuit is broken as illustrated in Fig. 1. In this way the degree of temperature to be maintained is lowered. Thus, our novel thermostatic device is therefore reversely adjustable to function at differing degrees of temperature and to respond differently under differing adjustments.

By providing the reduced stem or plunger 19 which travels in the small chamber 13, we gr atly increase the sensitivity of the device, since an expansion of the mercury which would tend to raise the level of the mercury 5 in the limbs 2 and 3 one quarter of an inch will raise the level of the mercury in the opening 13 and the plunger 19 a distance bearing the same proportion to one quarter of inch as the diameter of the chamber 13 bears to the diameters of limbs 2 and 3.

To guard against excessive elevation of the plunger elements 18 and 19 and their adjuncts due to excessive heat and expansion of the mercury 5 and the resultant disorganization of parts, we provide the overflow pocket 15 communicating with the upper end of the chamber 13 and into which any excess volume of mercury 5 can flow when the stem 19 has been raised so that its lower end clears the opening of said pocket, the bottom 16 of said pbcket being inclined (see Figs. 1 and 2) to facilitate the drainage of mercury back into the chamber 13, as soon as the mercury contracts, due to a decrease of temperature. It is of course understood that so long as the temperature varies between the desired predetermined limits, the lower end of the stem or plunger 19 and the level of the mercury in the opening 13 are always below the level of the overflow pocket 15, as will be seen from Fig. 1.

The bottom 46 of the cup 20 is inclined so as to facilitate the drainage of mercury 42 from said cup through the ports 21 and 22 into the side pocket 24 when the plunger 18 is in its uppermost position, said side pocket 24 serving as a reservoir in which the mercury 42 may be stored while the plunger 18 is in its uppermost position and it is desired to break the circuit, and serving to deliver or discharge the mercury 42 into the cup 20 when the plunger 18 has assumed its lower position and it is desired to complete the circuit.

In Fig. 5 we have shown a modified construction wherein we employ auxiliary electrical conductors 47 and 48 which lead to and energize a different machine or plant, and contact between which is established only when the mercury 42 is stored in the side pocket 24. Thus, when the temperature has reached the maximum limit and the mercury has been drained from the cup 20 through the bottom port 21 into the side pocket 24, contact is established between the terminals 47 and 48 and a cooling machine (or any other) is set in motion. When the plunger 18 has been lowered and the mercury 42 is discharged into the cup 20, to connect the wires 31 and 32, contact between the terminals 47 and 48 is broken and the cooling machine or other plant energized thereby is stopped.

It is of course understood that all air is exhausted from the limb extension 17 above the level of the mercury 5 in the chamber 13, so that the differential plunger or piston 18 and its adjuncts are free to move in a vacuum without having to overcome any air pressure which might otherwise seriously hamper the efficiency and accuracy of the device.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is:

1. In a device of the character stated, a U-shaped tube having limbs of different lengths and adapted to contain aliquid, a closure for the top of one of said limbs, a piston chamber formed in the other of said limbs, a movable piston in said chamher, said piston being cup-shaped at its top, and having a port therein near the bottom of the cup, and a passage in the wall of said piston chamber, having a lower port which is uncovered when said piston is in its lower position, said passage having an upper port which aligns with the port in said piston when the latter is in its uppermost position,

and electrical terminals positioned in. said cup.

In a device of the character stated, a U- shaped tube having limbs of different lengths and adapted to contain a liquid, a closure for the top of one of said limbs, a piston chamber formed in the other of said limbs, a movable piston in said chamber, said piston being cupshaped at its top and having a port therein near the bottom of the cup, a passage in the wall of said piston chamber having a lower port, which is uncovered when said piston is in its lower position, said passage having an upper port which aligns with the port in said piston when the latter is in its uppermost position, electrical terminals positioned in said cup, and an overflow chamber for the lower end of said piston.

3. In a device of the character U--sha ped tube having limbs of different lengths and adapted to contain a liquid, a closure for the top of one of said limbs, a piston chamber formed in the other of said limbs, a movable piston in said chamber, said piston being cup-shaped at its top and having a port therein near the bottom of the cup, a passage in the wall of said piston chamber having a lower port which is uncovered when said piston is in its lower position and an up; per portwhich aligns with the port in said piston when the latter is in its uppermost position, electrical terminals positioned in said cup, and means for preventing rotation of said piston.

4. In a device of the character stated, a U-shaped tube having limbs of different lengths and adapted to contain a liquid, a closure for the top of one of said limbs, a piston chamber formed in the other of said limbs, a movable piston in said chamber, said piston being cup shaped at its top, and having a port therein near the bottom of the cup, a passage in the wall of said piston chamber, having a lower port which is uncovered when said piston is in its lower position and an upper port which aligns with the port in said piston when the latter is in its uppermost position, electrical terminals positioned in said cup, and an adjustment plunger in one of said limbs.

In a device of the character stated, a U-shaped tube, having limbs of diiterent lengths, and adapted to contain a liquid, one of said limbs being closed at its top and the other having a contracted piston chamber therein, an upper extension of greater cross sectional area above said contracted chamher and forming an upper enlarged piston chamber and a differential piston in said chambers, having its larger area positioned in said upper chamber and its smaller lower area positioned in said contracted chamber.

6. In a device of the character stated, a U-shaped tube, having limbs of different lengths, and adapted to contain a liquid, one

stated, a

of said limbs being closed at its top and the other having a contracted piston chamber therein, an upper extension of greater cross sectional mm above said contracted chamher and forming an upper enlarged piston chamber, a differential piston in said chainbers, having its larger area positioned in said upper chamber and its smaller lower area positioned in said contracted chamber and circuit closing devices in said upper enlarged piston chamber.

7. In a device of the character stated, a U-shaped tube, having limbs of different lengths, a fluid partially filling said tube and limbs, a piston in the upper end of the longer limb, and adapted to rise and fall with the rise and tail of the fluid in said limb, a cup formed in the top of said piston and having a lower outlet port, electrical conductor terminals disposed in said cup, a side passage in a wall of said longer limb having upper and lower ports adapted to register and communicate with the bottom and top of said cup respectively to receive from and discharge into said cup an electrical conductor fluid to break and make electrical contact between said terininalsi 8. In a device of the character stated, a U-shaped tube, having limbs of different lengths, a fluid partially filling said tube and limbs, a piston in the upper end of the longer limb, and adapted to rise and fall with the rise and fall of the fluid in said limb, a cup formed in the top of said piston and having a lower outlet port, flexible, weighted, electrical conductor terminals disposed in said cup, a side passage in a wall of said longer limb having upper and lower ports adapted to register and communicate with the bottom and top of said cup respectively to receive from and discharge into said cup an electrical conductor fluid to break and make electrical contact between said terminals.

9. In a device of the character stated, a U tube having one limb formed into a piston chamber, a piston therein having a cup at its top, flexible electric terminals wighted at their bottom ends and positioned in said cup, an overflow chamber below said piston chamber. and a conductor liquid in said cup.

10. In a device of the character stated, a U tube having one limb formed into a piston chamber, a piston therein having a cup at its top, flexible electric terminals weighted at their bottom ends and positioned in said cup, an overflow chamber in proximity to said piston chamber, a conductor liquid in said cup, and a partition in said cup for separating said terminals.

11. In a device of the character stated, a U tube having one limb formed into a piston chamber, a piston therein having a cup at its top, provided with an inclined bottom wall, flexible electric terminals weighted at their bottom ends and positioned in said cup, an overflow chamber in proximity to said piston chamber and a conductor liquid in said cup.

12. In a device of the character stated, a U tube having one limb formed into a piston chamber, a piston therein having a cup at its top, flexible electric terminals weighted at their bottom ends and positioned in said cup, an apertured partition in said cup separating said terminals, and a conductor liquid in said cup, said cup having an inclined bottom and a port therein.

13. In a device of the character stated, a U-shaped tube having limbs of different lengths closed at their upper ends, a liquid partially filling said tube and limbs, an adj ustment plunger in the shorter limb, whereby the level of the fluid in said limbs may be varied, a lower restricted piston chamber and an upper enlarged piston chamber in the longer limb, a diflerential piston movable in said piston chambers, an annular overflow pocket having an inclined bottom communicating with said limb through said restricted piston chamber, a cup formed in the top of said piston, there being a port in the bottom of said cup, electrical terminals, positioned in said cup a passage in the wall of the longer limb having upper and lower ports communicating with said enlarged piston chamber and adapted to align with the port in the bottom of said cup and the top of said cup respectively, a partition in said cup for separating said terminals, there being a port in the bottom of said partition the bottom of said cup being inclined, and an electrical conductor fluid in said passage adapted to be discharged into said cup, to establish electrical contact between said terminals when said piston is in its lowermost position and to be discharged into said passage when said piston is in its uppermost position to break the electrical connection between said terminals, the rise and fall of said piston in said piston chambers being determined by the expansion and contraction of the liquid in said tube and limbs.

14. In a device of the character stated, a U-shaped tube having limbs of different lengths closed at their upper ends, a liquid partially filling said tube and limbs, an adjustment plunger in the shorter limb, whereby the level of the fluid in said limbs may be varied, a lower restricted piston chamber and an upper enlarged piston chamber in the longer limb, a diflerential piston movable in said piston chambers, an annular overflow pocket having an inclined bottom communicating with said limb through said restricted piston chamber, a cup formed in the top of said piston there being a port in the bottom of said cup, primary, flexible electrical terminals, having their lower ends wei hted positioned in said cup, a passage in the wall of the longer limb having upper and lower ports communicating with said enlarged piston chamber, and adapted to align with the port in the bottom of said cup and the top of said cup respectively, a partition in said cup for separating said terminals there being a port in the bottom of said partition, the bottom of said cup being inclined, an electrical conductor fluid in said passage adapted to be discharged into said cup to establish electrical contact between said terminals when said piston is in its lowermost position and to be discharged into said passage when said piston is in its uppermost position to break the electrical connection between said terminals, the rise and fall of said piston in said piston chambers being determined by the expansion and constraction of the liquid in said tube and limbs, and auxiliary electrical terminals positioned in said passage adapted to be electrically connected when said electrical conductor fluid is discharged from said cup into said passage and to be electrically disconnected when said fluid is discharged from said passage into said cup.

JOHN J. SIMMONS. RALPH J. DELANEY. 

